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The Spotless Garden

A system in Colorado uses wastewater from tilapia to nourish tomatoes. The tilapia are also food.Credit
Benjamin Rasmussen for The New York Times

THERE’S a “Beyond Thunderdome” quality to Rob Torcellini’s greenhouse. The 10-by-12-foot structure is undistinguished on the outside: he built it from a $700 kit, alongside his family’s Victorian-style farmhouse in Eastford, Conn., a former farming town 35 miles east of Hartford. What is going on inside, however, is either a glimpse at the future of food growing or a very strange hobby — possibly both.

There are fish here, for one thing, shivering through the winter, and a jerry-built system of tanks, heaters, pumps, pipes and gravel beds. The greenhouse vents run on a $20 pair of recycled windshield wiper motors, and a thermostat system sends Mr. Torcellini e-mail alerts when the temperature drops below 36 degrees. Some 500 gallons of water fill a pair of food-grade polyethylene drums that he scavenged from a light-industry park.

Mr. Torcellini’s greenhouse wouldn’t look out of place on a wayward space station where pioneers have gone to escape the cannibal gangs back on Earth. But then, in a literal sense, Mr. Torcellini, a 41-year-old I.T. director for an industrial manufacturer, has left earth — that is, dirt — behind.

What feeds his winter crop of lettuce is recirculating water from the 150-gallon fish tank and the waste generated by his 20 jumbo goldfish. Wastewater is what fertilizes the 27 strawberry plants from last summer, too. They occupy little cubbies in a seven-foot-tall PVC pipe. When the temperature begins to climb in the spring, he will plant the rest of the gravel containers with beans, peppers, tomatoes and cucumbers — all the things many other gardeners grow outside.

In here, though, the yields are otherworldly. “We actually kept a tally of how many cherry tomatoes we grew,” Mr. Torcellini said of last summer’s crop. “And from one plant, it was 347.” A trio of cucumber plants threw off 175 cukes.

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If that kind of bounty sounds hard to believe, Mr. Torcellini has a YouTube channel to demonstrate it. “There’s alternate ways of growing food,” he said. “I don’t want to push it down people’s throats, but if someone’s interested, I’d like to show them you can do this with cheap parts and a little bit of Yankee ingenuity.”

It’s all part of a home experiment he is conducting in a form of year-round, sustainable agriculture called aquaponics — a neologism that combines hydroponics (or water-based planting) and aquaculture (fish cultivation) — which has recently attracted a zealous following of kitchen gardeners, futurists, tinkerers and practical environmentalists.

And Australians — a lot of Australians.

In Australia, where gardeners have grappled with droughts for a decade, aquaponics is particularly appealing because it requires 80 to 90 percent less water than traditional growing methods. (The movement’s antipodean think tank is a Web site called Backyard Aquaponics, where readers can learn how, say, to turn a swimming pool into a fish pond.)

In the United States, aquaponics is in its fingerling stage, yet it seems to be increasing in popularity. Rebecca Nelson, 45, half of the company Nelson &Pade, publishes the Aquaponics Journal and sells aquaponics systems in Montello, Wis. While she refused to disclose exact sales figures, Ms. Nelson said that subscriptions have doubled every year for the last five years, and now number in the thousands. Having worked in the industry since 1997, leading workshops and consulting with academics, she estimates that there may be 800 to 1,200 aquaponics set-ups in American homes and yards and perhaps another 1,000 bubbling away in school science classrooms.

One of Ms. Nelson’s industry colleagues, Sylvia Bernstein, who helped develop a mass-market hydroponic product called the AeroGarden, recently turned her attention to aquaponics. She has started her own YouTube channel and a blog, and is teaching aquaponics at the Denver Botanic Gardens. She said she has done market research that suggests the technology may appeal to a half-dozen consumer types, including those seeking fresh winter herbs; gadget-happy gardeners; and high-income parents and their science-fair kids. But primarily, she envisions aquaponics as catnip for “the LOHAS market,” she said. “That means Lifestyles of Health and Sustainability — the green crowd.”

It’s worth mentioning that most of those categories would appear to describe the 47-year-old Ms. Bernstein. She built her first aquaponics system with her 15-year-old son on a concrete pad outside her remodeled 1970s-era Boulder, Colo., home. And she has since set up quarters in a 240-square-foot greenhouse. While she boasted about picking fresh basil the other day for a risotto, she has lately been preoccupied with exotic fish. Having tired of tilapia and trout, Ms. Bernstein is now introducing pacu, a thin, silvery import from South America that she called “a vegetarian piranha.”

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Rob Torcellini with lettuce from his aquaponics system in Connecticut.Credit
Douglas Healey for The New York Times

Aquaponics is addictive, Ms. Bernstein believes, and it has a way of becoming a full-time pursuit. “If you spend some time on Backyard Aquaponics,” she said, “people start with this little 100-gallon backyard system. But it never stays that way. Next thing, they’ll say, the tilapia were really cool, but I want to grow trout.”

Interested in aquaponics, but not ready to make it a life calling? No problem. An Atlanta company called Earth Solutions now sells kits online, on Amazon.com and the Home Depot’s Web site. Called Farm in a Box, they range in price from $268 to $3,000, and come with pipes, pumps, frames and fittings. David Epstein, 50, the osteopath and entrepreneur who invented Farm in a Box, reports that the company has sold several hundred units since the product went on sale last March.

Dr. Dave, as he likes to be called, created Farm in a Box after studying a do-it-yourself manual written by Travis W. Hughey — a creative debt that bothers Mr. Hughey not a bit.

Mr. Hughey, 49, is not just another proselytizer for aquaponics but, in his words, an “agri-missionary” who hopes to help feed the developing world. His free step-by-step plans have been downloaded more than 15,000 times since he started his site, Faith and Sustainable Technologies (fastonline.org), in 2007.

Mr. Hughey credits researchers at North Carolina State University for building the prototype that started the modern aquaponics movement some 25 years ago. By comparison, he came to aquaponics with little more than an unfinished biology degree at Oral Roberts University and a background in yacht repair, a career that required him to be “a jack of all trades, and a master of every one of them.”

The low-tech, low-cost design for his “Barrel-Ponics Manual” can be built out of three 55-gallon barrels, a pump, a wooden frame and some off-the-shelf hardware. One barrel, which sits on the ground, holds the fish. A second — split in half and filled with gravel — holds the plants. The final barrel, a storage or flush tank, perches above the other two like a toilet tank. The effluent-rich water that flows from one receptacle to the next is the life of the system, flooding the plants with nutrients and then trickling back into the fish tank.

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Sylvia Bernstein grows winter herbs and raises fish called pacu in Boudler, Colo.Credit
Benjamin Rasmussen for The New York Times

From these rudiments, all manner of aquaponics systems can be built. Mr. Hughey has nine of them going in a demonstration greenhouse outside the double-wide mobile home he shares with his wife and two daughters in Andrews, S.C. He has grown everything from radishes to a papaya tree in those barrels. Of course, his family could also eat the tilapia swimming around the 1,000-gallon in-ground plastic tank. But he’s saving them to use as brood stock.

This winter, he has begun construction on a pair of 1,200-square-foot aquaponics greenhouses to raise produce for the local natural foods market. Each one will take 80 barrel halves, 9 tons of gravel and a 3,000-gallon tilapia tank. The power for the pumps and heaters will come from a “hand-built” biodiesel generator. Mr. Hughey already has the fuel sitting in the yard: 12,000 gallons of vegetable oil that passed its expiration date.

He isn’t exactly stocking up for the end times. But with the way the economy is going, he said, it might not be a bad idea to have a backup plan to feed his family and neighbors. “I’m trying to make this place as self-reliant as possible,” he said. “But ultimately, self-reliance isn’t possible unless it’s profitable.”

There is something about aquaponics that seems to inspire this quirky blend of entrepreneurialism, environmentalism and survivalism. Even a mainstream businesswoman like Ms. Bernstein points to the water shortages in farming areas like the Central Valley in California — “to say nothing of Africa,” she added.

Jack Rowland can imagine a day when aquaponics set-ups could be built into new apartment complexes and be fed by municipal waste and geothermal power. In the meantime, he has started his own 1,200-gallon tilapia hatchery in his family’s unfinished basement in Wappingers Falls, N.Y., about 10 miles south of Poughkeepsie. He houses the fish in black cattle troughs, which have proved to be sturdy and nontoxic. A stock tank heater keeps the water at a comfortable 75 degrees.

Tilapia will tolerate crowding and will feast on your table scraps. (“They’re the ultimate garbage disposal unit,” Mr. Rowland said.) But, being tropical by nature, they die in the cold.

One of the pools is called the Dinner Tank. It is here that Mr. Rowland condemns his tilapia to a five-day fast before they make their way to the frying pan or the broiler. Tilapia, he said, do not deserve their bad reputation among cooks as the white bread of the waterways — mealy, pale and bland — but “you have to purge them or they taste gamey.”

“Most of the tilapia sold here was harvested months ago in China,” he said. “It’s like eating a fresh tomato versus what you buy in the grocery store.”

This summer, he hopes to transfer his operation from a spot next to the washer and dryer to a 50-foot-long hoop greenhouse. But he’s going about the project carefully. This attention to detail will most likely comfort Mr. Rowland’s neighbors: in his day job, Mr. Rowland, 57, is an outage planner for the Indian Point nuclear power plant.

Though Mr. Rowland spends perhaps an hour a night in the basement, looking for floaters and new spawn, he knows that no system is fail-safe. Pumps break, heaters go haywire. The art of aquaponics is one of trial and error.

“My mentor in the tilapia world told me I really wouldn’t be a master of tilapia until I killed at least a million fish,” he said. “I’m not there yet.”